Extended Work Shifts and Neurobehavioral Performance in Resident-Physicians

OBJECTIVES

Extended-duration work rosters (EDWRs) with shifts of 24+ hours impair performance compared with rapid cycling work rosters (RCWRs) that limit shifts to 16 hours in postgraduate year (PGY) 1 resident-physicians. We examined the impact of a RCWR on PGY 2 and PGY 3 resident-physicians.

METHODS

Data from 294 resident-physicians were analyzed from a multicenter clinical trial of 6 US PICUs. Resident-physicians worked 4-week EDWRs with shifts of 24+ hours every third or fourth shift, or an RCWR in which most shifts were ≤16 consecutive hours. Participants completed a daily sleep and work log and the 10-minute Psychomotor Vigilance Task and Karolinska Sleepiness Scale 2 to 5 times per shift approximately once per week as operational demands allowed.

RESULTS

Overall, the mean (± SE) number of attentional failures was significantly higher (P =.01) on the EDWR (6.8 ± 1.0) compared with RCWR (2.9 ± 0.7). Reaction time and subjective alertness were also significantly higher, by ∼18% and ∼9%, respectively (both P <.0001). These differences were sustained across the 4-week rotation. Moreover, attentional failures were associated with resident-physician-related serious medical errors (SMEs) (P =.04). Although a higher rate of SMEs was observed under the RCWR, after adjusting for workload, RCWR had a protective effect on the rate of SMEs (rate ratio 0.48 [95% confidence interval: 0.30-0.77]).

CONCLUSIONS

Performance impairment due to EDWR is improved by limiting shift duration. These data and their correlation with SME rates highlight the impairment of neurobehavioral performance due to extended-duration shifts and have important implications for patient safety.

Effect on Patient Safety of a Resident Physician Schedule without 24-Hour Shifts

BACKGROUND

The effects on patient safety of eliminating extended-duration work shifts for resident physicians remain controversial.

METHODS

We conducted a multicenter, cluster-randomized, crossover trial comparing two schedules for pediatric resident physicians during their intensive care unit (ICU) rotations: extended-duration work schedules that included shifts of 24 hours or more (control schedules) and schedules that eliminated extended shifts and cycled resident physicians through day and night shifts of 16 hours or less (intervention schedules). The primary outcome was serious medical errors made by resident physicians, assessed by intensive surveillance, including direct observation and chart review.

RESULTS

The characteristics of ICU patients during the two work schedules were similar, but resident physician workload, described as the mean (±SD) number of ICU patients per resident physician, was higher during the intervention schedules than during the control schedules (8.8±2.8 vs. 6.7±2.2). Resident physicians made more serious errors during the intervention schedules than during the control schedules (97.1 vs. 79.0 per 1000 patient-days; relative risk, 1.53; 95% confidence interval [CI], 1.37 to 1.72; P<0.001). The number of serious errors unitwide were likewise higher during the intervention schedules (181.3 vs. 131.5 per 1000 patient-days; relative risk, 1.56; 95% CI, 1.43 to 1.71). There was wide variability among sites, however; errors were lower during intervention schedules than during control schedules at one site, rates were similar during the two schedules at two sites, and rates were higher during intervention schedules than during control schedules at three sites. In a secondary analysis that was adjusted for the number of patients per resident physician as a potential confounder, intervention schedules were no longer associated with an increase in errors.

CONCLUSIONS

Contrary to our hypothesis, resident physicians who were randomly assigned to schedules that eliminated extended shifts made more serious errors than resident physicians assigned to schedules with extended shifts, although the effect varied by site. The number of ICU patients cared for by each resident physician was higher during schedules that eliminated extended shifts. (Funded by the National Heart, Lung, and Blood Institute; ROSTERS ClinicalTrials.gov number, NCT02134847.).

Effects on resident work hours, sleep duration, and work experience in a randomized order safety trial evaluating resident-physician schedules (ROSTERS)

STUDY OBJECTIVES

We compared resident physician work hours and sleep in a multicenter clustered-randomized crossover clinical trial that randomized resident physicians to an Extended Duration Work Roster (EDWR) with extended-duration (≥24 hr) shifts or a Rapidly Cycling Work Roster (RCWR), in which scheduled shift lengths were limited to 16 or fewer consecutive hours.

METHODS

Three hundred two resident physicians were enrolled and completed 370 1 month pediatric intensive care unit rotations in six US academic medical centers. Sleep was objectively estimated with wrist-worn actigraphs. Work hours and subjective sleep data were collected via daily electronic diary.

RESULTS

Resident physicians worked fewer total hours per week during the RCWR compared with the EDWR (61.9 ± 4.8 versus 68.4 ± 7.4, respectively; p < 0.0001). During the RCWR, 73% of work hours occurred within shifts of ≤16 consecutive hours. In contrast, during the EDWR, 38% of work hours occurred on shifts of ≤16 consecutive hours. Resident physicians obtained significantly more sleep per week on the RCWR (52.9 ± 6.0 hr) compared with the EDWR (49.1 ± 5.8 hr, p < 0.0001). The percentage of 24 hr intervals with less than 4 hr of actigraphically measured sleep was 9% on the RCWR and 25% on the EDWR (p < 0.0001).

CONCLUSIONS

RCWRs were effective in reducing weekly work hours and the occurrence of >16 consecutive hour shifts, and improving sleep duration of resident physicians. Although inclusion of the six operational healthcare sites increases the generalizability of these findings, there was heterogeneity in schedule implementation. Additional research is needed to optimize scheduling practices allowing for sufficient sleep prior to all work shifts.Clinical Trial: Multicenter Clinical Trial of Limiting Resident Work Hours on ICU Patient Safety (ROSTERS), https://clinicaltrials.gov/ct2/show/NCT02134847.

Randomized, Placebo-Controlled Trial of Ferrous Sulfate to Treat Insomnia in Children With Autism Spectrum Disorders

BACKGROUND

Insomnia and low iron stores are common in children with autism spectrum disorders, and low iron stores have been associated with sleep disturbance.

METHODS

We performed a randomized placebo-controlled trial of oral ferrous sulfate to treat insomnia in children with autism spectrum disorders and low normal ferritin levels. Twenty participants who met inclusion criteria and whose insomnia did not respond to sleep education were randomized to 3 mg/kg/day of ferrous sulfate (n = 9) or placebo (n = 11) for three months.

RESULTS

Iron supplementation was well tolerated, and no serious adverse events were reported. Iron supplementation improved iron status (+18.4 ng/mL active versus -1.6 ng/mL placebo, P = 0.044) but did not significantly improve the primary outcome measures of sleep onset latency (-11.0 minutes versus placebo, 95% confidence interval -28.4 to 6.4 minutes, P = 0.22) and wake time after sleep onset (-7.7 minutes versus placebo, 95% confidence interval -22.1 to 6.6 min, P = 0.29) as measured by actigraphy. Iron supplementation was associated with improvement in the overall severity score from the Sleep Clinical Global Impression Scale (-1.5 points versus placebo, P = 0.047). Changes in measures of daytime behavior did not differ between groups.

CONCLUSION

This trial demonstrated no improvement in primary outcome measures of insomnia in subjects treated with ferrous sulfate compared with placebo. Interpretation was limited by low enrollment.

Nocturnal Hypoxia Activation of the Hedgehog Signaling Pathway Affects Pediatric Nonalcoholic Fatty Liver Disease Severity

Chronic intermittent hypoxia and hedgehog (Hh) pathway dysregulation are associated with nonalcoholic fatty liver disease (NAFLD) progression. In this study, we determined the relationship between obstructive sleep apnea (OSA)/nocturnal hypoxia and Hh signaling in pediatric NAFLD. Adolescents with histologic NAFLD (n = 31) underwent polysomnogram testing, laboratory testing, and Sonic Hh (SHh), Indian hedgehog (IHh), glioblastoma‐associated oncogene 2 (Gli2), keratin 7 (K7), α‐smooth muscle actin (α‐SMA), and hypoxia‐inducible factor 1α (HIF‐1α) immunohistochemistry. Aspartate aminotransferase (AST) correlated with SHh, r = 0.64; Gli2, r = 0.4; α‐SMA, r = 0.55; and K7, r = 0.45 (P < 0.01), as did alanine aminotransferase (ALT) (SHh, r = 0.51; Gli2, r = 0.43; α‐SMA, r = 0.51; P < 0.02). SHh correlated with NAFLD activity score (r = 0.39), whereas IHh correlated with inflammation (r = −0.478) and histologic grade (r = −0.43); P < 0.03. Subjects with OSA/hypoxia had higher SHh (4.0 ± 2.9 versus 2.0 ± 1.5), Gli2 (74.2 ± 28.0 versus 55.8 ± 11.8), and α‐SMA (6.2 ± 3.3 versus 4.3 ± 1.2); compared to those without (P < 0.03). OSA severity correlated with SHh (r = 0.31; P = 0.09) and Gli2 (r = 0.37; P = 0.04) as did hypoxia severity, which was associated with increasing SHh (r = −0.53), Gli2 (r = −0.52), α‐SMA (r = −0.61), and K7 (r = −0.42); P < 0.02. Prolonged O₂ desaturations <90% also correlated with SHh (r = 0.55) and Gli2 (r = 0.61); P < 0.05. Conclusion: The Hh pathway is activated in pediatric patients with NAFLD with nocturnal hypoxia and relates to disease severity. Tissue hypoxia may allow for functional activation of HIF‐1α, with induction of genes important in epithelial‐mesenchymal transition, including SHh, and NAFLD progression.

The Impact of Altitude on Sleep-Disordered Breathing in Children Dwelling at High Altitude: A Crossover Study

Study Objectives

Sleep-disordered breathing (SDB) is prevalent among children and is associated with adverse health outcomes. Worldwide, approximately 250 million individuals reside at altitudes higher than 2000 meters above sea level (masl). The effect of chronic high-altitude exposure on children with SDB is unknown. This study aims to determine the impact of altitude on sleep study outcomes in children with SDB dwelling at high altitude.

Methods

A single-center crossover study was performed to compare results of high-altitude home polysomnography (H-PSG) with lower altitude laboratory polysomnography (L-PSG) in school-age children dwelling at high altitude with symptoms consistent with SDB. The primary outcome was apnea-hypopnea index (AHI), with secondary outcomes including obstructive AHI; central AHI; and measures of oxygenation, sleep quality, and pulse rate.

Results

Twelve participants were enrolled, with 10 included in the final analysis. Median altitude was 1644 masl on L-PSG and 2531 masl on H-PSG. Median AHI was 2.40 on L-PSG and 10.95 on H-PSG. Both obstructive and central respiratory events accounted for the difference in AHI. Oxygenation and sleep fragmentation were worse and pulse rate higher on H-PSG compared to L-PSG.

Conclusions

These findings reveal a clinically substantial impact of altitude on respiratory, sleep, and cardiovascular outcomes in children with SDB who dwell at high altitude. Within this population, L-PSG underestimates obstructive sleep apnea and central sleep apnea compared to H-PSG. Given the shortage of high-altitude pediatric sleep laboratories, these results suggest a role for home sleep apnea testing for children residing at high altitude.

LIBS

Excerpted from "A Lightweight and Inexpensive In-ear Sensing System For Automatic Whole-night Sleep Stage Monitoring," from ACM SenSys 2016, Proceedings of the 14th ACM Conference on Embedded Network Sensor Systems, with permission. http://dl.acm.org/citation.cfm?id=2994562 ACM 2016

Family Chaos and Child Functioning in Relation to Sleep Problems Among Children at Risk for Obesity

This study evaluated the influence of child and family functioning on child sleep behaviors in low-income minority families who are at risk for obesity. A cross-sectional study was utilized to measure child and family functioning from 2013 to 2014. Participants were recruited from Head Start classrooms while data were collected during home visits. A convenience sample of 72 low-income Hispanic (65%) and African American (32%) families of preschool-aged children were recruited for this study. We assessed the association of child and family functioning with child sleep behaviors using a multivariate multiple linear regression model. Bootstrap mediation analyses examined the effects of family chaos between child functioning and child sleep problems. Poorer child emotional and behavioral functioning related to total sleep behavior problems. Chaos associated with bedtime resistance significantly mediated the relationship between Behavioral and Emotional Screening System (BESS) and Bedtime Resistance. Families at high risk for obesity showed children with poorer emotional and behavioral functioning were at higher risk for problematic sleep behaviors, although we found no link between obesity and child sleep. Family chaos appears to play a significant role in understanding part of these relationships. Future longitudinal studies are necessary to establish causal relationships between child and family functioning and sleep problems to further guide obesity interventions aimed at improving child sleep routines and increasing sleep duration.

An Official American Thoracic Society Clinical Practice Guideline: Pediatric Chronic Home Invasive Ventilation

BACKGROUND

Children with chronic invasive ventilator dependence living at home are a diverse group of children with special health care needs. Medical oversight, equipment management, and community resources vary widely. There are no clinical practice guidelines available to health care professionals for the safe hospital discharge and home management of these complex children.

PURPOSE

To develop evidence-based clinical practice guidelines for the hospital discharge and home/community management of children requiring chronic invasive ventilation.

METHODS

The Pediatric Assembly of the American Thoracic Society assembled an interdisciplinary workgroup with expertise in the care of children requiring chronic invasive ventilation. The experts developed four questions of clinical importance and used an evidence-based strategy to identify relevant medical evidence. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to formulate and grade recommendations.

RESULTS

Clinical practice recommendations for the management of children with chronic ventilator dependence at home are provided, and the evidence supporting each recommendation is discussed.

CONCLUSIONS

Collaborative generalist and subspecialist comanagement is the Medical Home model most likely to be successful for the care of children requiring chronic invasive ventilation. Standardized hospital discharge criteria are suggested. An awake, trained caregiver should be present at all times, and at least two family caregivers should be trained specifically for the child's care. Standardized equipment for monitoring, emergency preparedness, and airway clearance are outlined. The recommendations presented are based on the current evidence and expert opinion and will require an update as new evidence and/or technologies become available.

Knowledge, Attitudes, and Risk for Sudden Unexpected Infant Death in Children of Adolescent Mothers: A Qualitative Study

OBJECTIVE

To investigate practices, knowledge, attitudes, and beliefs regarding infant sleep among adolescent mothers, a demographic at high risk for sudden unexpected infant death, and to identify novel public health interventions targeting the particular reasons of this population.

STUDY DESIGN

Seven targeted focus groups including 43 adolescent mothers were conducted at high school daycare centers throughout Colorado. Focus groups were recorded, transcribed, validated, and then analyzed in NVivo 10. Validation included coding consistency statistics and expert review.

RESULTS

Most mothers knew many of the American Academy of Pediatrics recommendations for infant sleep. However, almost all teens reported bedsharing regularly and used loose blankets or soft bedding despite being informed of risks. Reasons for nonadherence to recommendations included beliefs that babies are safest and sleep more/better in bed with them, that bedsharing is a bonding opportunity, and that bedsharing is easier than using a separate sleep space. The most common justifications for blankets were infant comfort and concern that babies were cold. Participants' decision making was often influenced by their own mothers, with whom they often resided. Participants felt that their instincts trumped professional advice, even when in direct contradiction to safe sleep recommendations.

CONCLUSIONS

Among focus group participants, adherence with safe sleep practices was poor despite awareness of the American Academy of Pediatrics recommendations. Many mothers expressed beliefs and instincts that infants were safe in various unsafe sleep environments. Future study should investigate the efficacy of alternative educational strategies, including education of grandmothers, who have significant influence over adolescent mothers.

Food Dye Use in Enteral Feedings: A Review and a Call for a Moratorium

Pulmonary aspiration of gastric contents is common in enterally fed patients. Tinting enteral feedings with blue dye is thought to aid the early detection of aspiration in hospitalized patients. The blue-dye method is popular despite evidence that it is not sensitive. Reports of absorption of blue dye from enteral feedings in patients with sepsis and other critical illnesses are increasing. The presence of blue and green skin and urine, and serum discoloration has been linked with death. FD&C Blue No.1 and related dyes have toxic effects on mitochondria, suggesting that dye absorption is harmful. This study reviews the literature on the dye method and dye pharmacology, reports the results of a survey of current dye use, and describes 2 recent deaths associated with blue-dye absorption. We concluded that the use of blue dye in enteral feedings should be abandoned and replaced by evidence-based methods for the prevention of aspiration.

Comparative meta-analysis of prazosin and imagery rehearsal therapy for nightmare frequency, sleep quality, and posttraumatic stress

STUDY OBJECTIVE

In this meta-analysis, we compare the short-term efficacy of prazosin vs. IRT on nightmares, sleep quality, and posttraumatic stress symptoms (PTSS).

METHODS

Reference databases were searched for randomized controlled trials using IRT or prazosin for nightmares, sleep disturbance, and/or PTSS. Effect sizes were calculated by subtracting the mean posttest score in the control group from the mean posttest score in the treatment group, and dividing the result by the pooled standard deviation of both groups. Mixed effects models were performed to evaluate effects of treatment characteristics, as well as sample characteristics (veteran vs. civilian) on treatment efficacy.

RESULTS

Four studies used prazosin, 10 used IRT alone or in combination with another psychological treatment, and 1 included a group receiving prazosin and another group receiving IRT. Overall effect sizes of both treatments were of moderate magnitude for nightmare frequency, sleep quality, and PTSS (p < 0.01). Effect size was not significantly different with type of treatment (psychological vs. pharmacological) on nightmare frequency (p = 0.79), sleep quality (p = 0.65), or PTSS, (p = 0.52). IRT combined with CBT for insomnia showed more improvement in sleep quality compared to prazosin (p = 0.03), IRT alone (p = 0.03), or IRT combined with another psychological intervention, (p < 0.01).

CONCLUSION

Although IRT interventions and prazosin yield comparable acute effects for the treatment of nightmares, adding CBT for insomnia to IRT seems to enhance treatment outcomes pertaining to sleep quality and PTSS. More randomized clinical trials with long-term follow-up are warranted.

COMMENTARY

A commentary on this article appears in this issue on page 9.

Evaluation of a new pediatric positive airway pressure mask

STUDY OBJECTIVES

The choice and variety of pediatric masks for continuous positive airway pressure (CPAP) is limited in the US. Therefore, clinicians often prescribe modified adult masks. Until recently a mask for children aged < 7 years was not available. This study evaluated apnea-hypopnea index (AHI) equivalence and acceptability of a new pediatric CPAP mask for children aged 2-7 years (Pixi; ResMed Ltd, Sydney, Australia).

METHODS

Patients aged 2-7 years were enrolled and underwent in-lab baseline polysomnography (PSG) using their previous mask, then used their previous mask and the VPAP III ST-A flow generator for ≥ 10 nights at home. Thereafter, patients switched to the Pixi mask for ≥ 2 nights before returning for a PSG during PAP therapy via the Pixi mask. Patients then used the Pixi mask at home for ≥ 21 nights. Patients and their parents/guardians returned to the clinic for follow-up and provided feedback on the Pixi mask versus their previous mask.

RESULTS

AHI with the Pixi mask was 1.1 ± 1.5/h vs 2.6 ± 5.4/h with the previous mask (p = 0.3538). Parents rated the Pixi mask positively for: restfulness of the child's sleep, trouble in getting the child to sleep, and trouble in having the child stay asleep. The Pixi mask was also rated highly for leaving fewer or no marks on the upper lip and under the child's ears, and being easy to remove.

CONCLUSIONS

The Pixi mask is suitable for children aged 2-7 years and provides an alternative to other masks available for PAP therapy in this age group.

Obstructive sleep apnea and hypoxemia are associated with advanced liver histology in pediatric nonalcoholic fatty liver disease

OBJECTIVE

To determine whether obstructive sleep apnea (OSA) and/or nocturnal hypoxemia are associated with the severity of liver injury in patients with pediatric nonalcoholic fatty liver disease (NAFLD).

STUDY DESIGN

Obese children aged 10-18 years with liver biopsy-proven NAFLD were enrolled. Demographic, clinical, and laboratory data were collected, polysomnography was performed, and liver histology was scored. Subjects were divided into those with OSA/hypoxemia and those without OSA/hypoxemia for analysis.

RESULTS

Of 25 subjects with NAFLD, OSA/hypoxemia was present in 15 (60%) (mean age, 12.8 ± 1.9 years; 68% male; 88% Hispanic; mean body mass index z-score, 2.3 ± 0.3). Subjects with and without OSA/hypoxemia had similar levels of serum aminotransferases, serum lipids, and inflammatory and insulin resistance markers. Although there were no differences between groups in the histological severity of steatosis, inflammation, ballooning degeneration, NAFLD activity score, or histological grade, subjects with OSA/hypoxemia had significantly more severe hepatic fibrosis. Moreover, oxygen saturation nadir during polysomnography was related to hepatic fibrosis stage (r = -0.49; P = .01) and aspartate aminotransferase level (r = 0.42; P < .05). Increasing percentage of time with oxygen saturation ≤90% was related to NAFLD inflammation grade (r = 0.44; P = .03), degree of hepatic steatosis (r = -0.50; P = .01), NAFLD activity score (r = 0.42; P = .04), aspartate aminotransferase level (r = 0.56; P = .004), and alanine aminotransferase level (r = 0.44; P = .03).

CONCLUSION

Moderate OSA/hypoxemia is common in pediatric patients with biopsy-proven NAFLD. OSA and the severity/duration of hypoxemia are associated with biochemical and histological measures of NAFLD severity.

Heterogeneous pulmonary phenotypes associated with mutations in the thyroid transcription factor gene NKX2-1

BACKGROUND

Mutations in the gene encoding thyroid transcription factor, NKX2-1, result in neurologic abnormalities, hypothyroidism, and neonatal respiratory distress syndrome (RDS) that together are known as the brain-thyroid-lung syndrome. To characterize the spectrum of associated pulmonary phenotypes, we identified individuals with mutations in NKX2-1 whose primary manifestation was respiratory disease.

METHODS

Retrospective and prospective approaches identified infants and children with unexplained diffuse lung disease for NKX2-1 sequencing. Histopathologic results and electron micrographs were assessed, and immunohistochemical analysis for surfactant-associated proteins was performed in a subset of 10 children for whom lung tissue was available.

RESULTS

We identified 16 individuals with heterozygous missense, nonsense, and frameshift mutations and five individuals with heterozygous, whole-gene deletions of NKX2-1. Neonatal RDS was the presenting pulmonary phenotype in 16 individuals (76%), interstitial lung disease in four (19%), and pulmonary fibrosis in one adult family member. Altogether, 12 individuals (57%) had the full triad of neurologic, thyroid, and respiratory manifestations, but five (24%) had only pulmonary symptoms at the time of presentation. Recurrent respiratory infections were a prominent feature in nine subjects. Lung histopathology demonstrated evidence of disrupted surfactant homeostasis in the majority of cases, and at least five cases had evidence of disrupted lung growth.

CONCLUSIONS

Patients with mutations in NKX2-1 may present with pulmonary manifestations in the newborn period or during childhood when thyroid or neurologic abnormalities are not apparent. Surfactant dysfunction and, in more severe cases, disrupted lung development are likely mechanisms for the respiratory disease.

Respiratory and polysomnographic values in 3- to 5-year-old normal children at higher altitude

STUDY OBJECTIVES

To determine polysomnographic parameter differences in children living at higher altitude to children living near sea level.

DESIGN AND SETTING

Prospective study of non-snoring, normal children recruited from various communities around Denver, CO. In-lab, overnight polysomnograms were performed at a tertiary care children's hospital. All children required residence for greater than one year at an elevation around 1,600 meters.

PARTICIPANTS

45 children (62% female), aged 3-5 years, 88.9% non-Hispanic white with average BMI percentile for age of 47.8% ± 30.7%.

MEASUREMENTS AND RESULTS

Standard sleep indices were obtained and compared to previously published normative values in a similar population living near sea level (SLG). In the altitude group (AG), the apnea-hypopnea index was 1.8 ± 1.2 and the central apnea-hypopnea index was 1.7 ± 1.1, as compared to 0.9 ± 0.8 and 0.8 ± 0.7, respectively, (P ≤ 0.005) in SLG. Mean end-tidal CO2 level in AG was 42.3 ± 3.0 mm Hg and 40.6 ± 4.6 mm Hg in SLG (P = 0.049). The ≥ 4% desaturation index was 3.9 ± 2.0 in AG compared to 0.3 ± 0.4 in SLG (P < 0.001). Mean periodic limb movement in series index was 10.1 ± 12.3 in AG and 3.6 ± 5.4 in SLG (P = 0.001).

CONCLUSION

Comparison of altitude and sea level sleep studies in healthy children reveals significant differences in central apnea, apneahypopnea, desaturation, and periodic limb movement in series indices. Clinical providers should be aware of these differences when interpreting sleep studies and incorporate altitude-adjusted normative values in therapeutic-decision making algorithms.

An official American thoracic society statement: position statement on ATS activities for the promotion of respiratory and sleep/wake health and the care of the critically ill in the United States

BACKGROUND

The 1997 American Thoracic Society (ATS) statement "A Framework for Health Care Policy in the United States" outlined core principles for the Society's activities in the public health arena. In the succeeding 10 years, profound changes have taken place in the United States health care environment. In addition, the 2005 publication of the Society's Vision highlighted some differences between the original Statement and our current priorities. Therefore, the Health Policy Committee embarked on a re-analysis and re-statement of the Society's attitudes and strategies with respect to health and public policy. This Statement reflects the findings of the Committee.

PURPOSE

To outline the key aspects of an internal ATS strategy for the promotion of respiratory and sleep/wake health and the care of the critically ill in the United States.

METHODS

Committee discussion and consensus-building occurred both before and after individual members performed literature searches and drafted sections of the document. Comments were solicited on the draft document from ATS committee and assembly chairs and the Executive Committee, resulting in substantive revisions of the final document.

RESULTS

Specific strategies are suggested for the ATS in the arenas of research, training and education, patient care, and advocacy so as to enhance the delivery of health care in the fields of respiratory medicine, sleep medicine, and critical care.

CONCLUSIONS

The American Thoracic Society's Mission, Core Principles, and Vision provide clear guidance for the formulation of specific strategies that will serve to promote improved respiratory health and care of the critically ill in the United States.

Pediatric home apnea monitors: coding, billing, and updated prescribing information for practice management

A series of new current procedural terminology codes have been created that allow health-care providers to code and bill for pediatric home apnea monitoring in the United States. Apnea monitors have been used at home on pediatric patients at risk for sudden death for > 30 years without the benefit of evidence-based efficacy studies. Nevertheless, new apnea monitor devices with expanded capability have been developed. Recommended indications for pediatric home apnea monitors are outdated and vague. It is important for the prescribing health-care provider to understand device function, as well as the pathophysiology of cardiorespiratory events in different disease states in order to make logical decisions about which monitor to prescribe, or whether to prescribe one at all. This article will review what apnea monitors are designed to do, common misperceptions about device indications vs device capability, and updated suggestions regarding the prescription, billing, and coding of pediatric apnea monitors for pediatric practice management.

Childhood obstructive sleep-disordered breathing: a clinical update and discussion of technological innovations and challenges

Childhood sleep-disordered breathing (SDB) has been known to be associated with health and cognitive impacts for more than a century, and yet our understanding of this disorder is in its infancy. Neuropsychological consequences in children with snoring or subtle breathing disturbances not meeting the traditional definition of sleep apnea suggest that "benign, or primary snoring" may be clinically significant, and that the true prevalence of SDB might be underestimated. There is no standard definition of SDB in children. The polysomnographic technology used in many sleep laboratories may be inadequate to diagnose serious but subtle forms of clinically important airflow limitation. In the last several years, advances in digital technology as well as new observational studies of respiratory and arousal patterns in large populations of healthy children have led to alternative views of what constitutes sleep-related breathing and arousal abnormalities that may refine our diagnostic criteria. This article reviews our knowledge of childhood SDB, highlights recent advances in technology, and discusses diagnostic and treatment strategies that will advance the management of children with pediatric SDB.

Behavioral training for increasing preschool children's adherence with positive airway pressure: a preliminary study

Behavioral training was implemented to increase adherence with positive airway pressure (PAP) in 4 preschool children. The training employed distraction, counterconditioning, graduated exposure, differential reinforcement, and escape extinction. A non-concurrent multiple baseline experimental design was used to demonstrate program effects. Initially, the children displayed distress and escape-avoidance behavior when PAP was attempted. With training, all 4 children tolerated PAP while sleeping for age appropriate durations. For the 3 children with home follow-up data, the parents maintained benefits. The results are discussed in relation to behavior principles, child health, and common barriers to PAP adherence.

Childhood obstructive sleep apnea associates with neuropsychological deficits and neuronal brain injury

BACKGROUND

Childhood obstructive sleep apnea (OSA) is associated with neuropsychological deficits of memory, learning, and executive function. There is no evidence of neuronal brain injury in children with OSA. We hypothesized that childhood OSA is associated with neuropsychological performance dysfunction, and with neuronal metabolite alterations in the brain, indicative of neuronal injury in areas corresponding to neuropsychological function.

METHODS AND FINDINGS

We conducted a cross-sectional study of 31 children (19 with OSA and 12 healthy controls, aged 6-16 y) group-matched by age, ethnicity, gender, and socioeconomic status. Participants underwent polysomnography and neuropsychological assessments. Proton magnetic resonance spectroscopic imaging was performed on a subset of children with OSA and on matched controls. Neuropsychological test scores and mean neuronal metabolite ratios of target brain areas were compared. Relative to controls, children with severe OSA had significant deficits in IQ and executive functions (verbal working memory and verbal fluency). Children with OSA demonstrated decreases of the mean neuronal metabolite ratio N-acetyl aspartate/choline in the left hippocampus (controls: 1.29, standard deviation [SD] 0.21; OSA: 0.91, SD 0.05; p = 0.001) and right frontal cortex (controls: 2.2, SD 0.4; OSA: 1.6, SD 0.4; p = 0.03).

CONCLUSIONS

Childhood OSA is associated with deficits of IQ and executive function and also with possible neuronal injury in the hippocampus and frontal cortex. We speculate that untreated childhood OSA could permanently alter a developing child's cognitive potential.

Neuropsychological morbidity linked to childhood sleep-disordered breathing

Understanding the long-term neuropsychological consequences of sleep disorders in children poses a significant challenge to researchers. Since children are in a state of rapidly changing cognition and neurobehavioral function, impacts on development may have profound consequences. Recent studies now demonstrate that mild sleep apnea and snoring, once considered within the spectrum of normal sleep patterns, are associated with deficits of neuropsychological function. Preliminary data suggest that some of these cognitive deficits may be reversible following treatment of mild sleep apnea in children; however, factors such as age at treatment, duration of sleep disordered breathing, pre-morbid intellectual level, socioeconomic status, or the effectiveness of treatment may adversely affect long-term outcome. Furthermore, it is imperative that researchers determine whether the developing brain exhibits critical periods of plasticity during which episodes of sleep-disordered breathing might cause long-term or permanent neuropsychological effects.

Relief of Upper Airway Obstruction With Mandibular Distraction Surgery

OBJECTIVE

To evaluate the long-term benefits of mandibular distraction on sleep-related upper airway obstruction in young children with mandibular hypoplasia.

DESIGN

Cross-sectional study. Subjects were examined for sleep-disordered breathing using medical history, physical examination results, and a written questionnaire. Subjects underwent standard overnight polysomnography, during which measures of sleep-disordered breathing were collected.

SETTING

Tertiary care hospital.

PATIENTS

Five children with upper airway obstruction from craniofacial anomalies treated with mandibular distraction, with a minimum follow-up of 12 months.

MAIN OUTCOME MEASURES

Apnea-hypopnea index, oxygen saturation nadir, and peak end-tidal carbon dioxide value.

RESULTS

Of the 5 children, 3 were cured of upper airway obstruction as documented by polysomnography, with an apnea-hypopnea index of less than 1.5 and no snoring. The fourth child had primary snoring without apnea. The fifth child had severe obstructive sleep apnea, with an apnea-hypopnea index of 20.2.

CONCLUSIONS

Most children who undergo mandibular distraction for upper airway obstruction associated with mandibular hypoplasia demonstrate significant clinical improvement of obstructive sleep apnea. However, those children who continue to have symptoms of sleep-disordered breathing after surgery should undergo polysomnography for evaluation of persistent obstructive sleep apnea.

Adherence to and effectiveness of positive airway pressure therapy in children with obstructive sleep apnea

OBJECTIVES

Positive airway pressure therapy (PAP) is frequently used to treat children who have obstructive sleep apnea syndrome and do not respond to adenotonsillectomy. However, no studies have evaluated objectively adherence to PAP in children, and few studies have evaluated objectively the effectiveness of PAP. The objective of this study was to determine adherence and effectiveness of PAP (both continuous [CPAP] and bilevel [BPAP] pressure) in children with obstructive apnea.

METHODS

A prospective, multicenter study was performed of children who were randomly assigned in a double-blind manner to 6 months of CPAP versus BPAP. Adherence was measured objectively using the equipment's computerized output. Effectiveness was evaluated using polysomnography.

RESULTS

Twenty-nine children were studied. Approximately one third of children dropped out before 6 months. Of the 21 children for whom 6-month adherence data could be downloaded, the mean nightly use was 5.3 +/- 2.5 (SD) hours. Parental assessment of PAP use considerably overestimated actual use. PAP was highly effective, with a reduction in the apnea hypopnea index from 27 +/- 32 to 3 +/- 5/hour, and an improvement in arterial oxygen saturation nadir from 77 +/- 17% to 89 +/- 6%. Results were similar for children who received CPAP versus BPAP. Children also had a subjective improvement in daytime sleepiness.

CONCLUSIONS

Both CPAP and BPAP are highly efficacious in pediatric obstructive apnea. However, treatment with PAP is associated with a high dropout rate, and even in the adherent children, nightly use is suboptimal considering the long sleep hours in children.

Sleep disturbance after rapid ascent to moderate altitude among infants and preverbal young children

Rapid ascent to high altitude is known to result in sleep disturbances among adults. No data exist regarding the effects of altitude exposure on sleep in children. The objective of this study was to determine the effect of rapid ascent to moderate altitude on sleep in infants and young children. In this prospective study, each child served as his or her own control. Each subject was studied over 7 days and nights. On days 1 and 2, children were studied at home (1601 m), day 3 at a hotel without ascent (travel control), day 4 at home, days 5 and 6 at a hotel after ascent (3109 m), and day 7 at home. Since increased motion is a characteristic of sleep disturbance among infants and young children, continuous measurements of motion were made using an ankle-mounted Actigraph. Thirty children, 17 girls and 13 boys, with a median age of 16.5 months (range = 4 to 33 months) participated in the study. Significant changes in the activity counts, reflecting a sleep disturbance during nocturnal sleep, were noted between the travel control night (20.9 +/- 1.9) and the first night at altitude (29.4 +/- 2.5): p < 0.01. This sleep disturbance is most significant during the first night at altitude and may be similar to sleep disturbance with altitude exposure seen in adults.

Sleep disorders in children

PURPOSE OF REVIEW

Childhood sleep disorders are one of the most prevalent complaints in the pediatrician's office. Infant sleep rhythm complaints from new mothers reach 46%, while childhood obstructive sleep apnea has a prevalence of 2% and adolescent insomnia with daily consequences surpasses that percentage.

RECENT FINDINGS

Each sleep disorder must be considered in context of age, as age influences the presentation and impact on the developing child or adolescent. For example, sleep-disordered breathing resulting in adult sleepiness can contribute to death in infants. The symptoms of narcolepsy are often masked until after adolescence, resulting in psychologically costly misdiagnoses.

SUMMARY

There are no outcome studies that track the long-term consequences of pediatric sleep disorders or their contribution to adult sleep problems, but this is an area of increasing research interest. This review assesses the most recent literature on pediatric sleep disorders from May 1, 2002, until April 30, 2003.

Secondary narcolepsy in children with brain tumors

We report two cases of children with disabling daytime sleepiness associated with suprasellar tumors and hypothalamic obesity. Multiple sleep latency testing demonstrated features consistent with severe narcolepsy, with sleep latencies of 0.25 and 0.75 minutes, and REM latencies of 2.1 and 1.5 minutes, respectively. An additional patient with hypothalamic damage secondary to a brain tumor, who was thought to be in a vegetative state, had features of narcolepsy on polysomnography. All children responded well to treatment with stimulants. We speculate that secondary narcolepsy associated with hypothalamic tumors is due to damage or loss of hypothalamic hypocretin-containing neurons. In view of the good response to treatment, we recommend that all children with excessive daytime sleepiness and hypothalamic damage be evaluated for narcolepsy.

Physiologic reflexes and their impact on resuscitation of the newborn

Most depressed newborn infants respond promptly to minimal intervention. When that does not happen, a thorough understanding of the physiologic reflexes that promote and prevent, prompt restoration of heart rate, blood pressure, and respiration is crucial. This article will review data demonstrating that lung inflation, in the purely mechanical sense, is a key element in a successful resuscitation. A complicated resuscitation is most often because of the caretaker's lack of awareness of basic cardiopulmonary physiology than to an unusually depressed infant.

Chronic intrauterine pulmonary hypertension impairs endothelial nitric oxide synthase in the ovine fetus

Endothelial (e) nitric oxide synthase (NOS) activity modulates pulmonary vascular tone in the normal fetus and decreases pulmonary vascular resistance (PVR) at birth. Mechanisms contributing to sustained elevations of PVR and the failure of postnatal adaptation at birth are uncertain but may include decreased eNOS activity. To test this hypothesis, we studied the effects of chronic intrauterine pulmonary hypertension on lung eNOS content and NOS activity in an ovine model of perinatal pulmonary hypertension and in normal lambs. We measured eNOS mRNA and protein content by Northern and Western blot analyses, respectively. Calcium-dependent and total NOS activities were determined by assaying the conversion of L-[14C]arginine to L-[14C]citrulline from lung homogenates. To determine the effects of intrauterine hypertension on lung eNOS content, fetal lung tissue was harvested 8-12 days after intrauterine closure of the ductus arteriosus (DA) performed at 125-128 days of gestation (term = 147 days). Although positive immunostaining for eNOS persisted in lung vascular endothelium, eNOS protein content was reduced by 48%, as measured by Western analysis (P < 0.001). Chronic hypertension reduced lung eNOS mRNA content by 30% (P < 0.05). Compared with age-matched controls, Ca(2+)-dependent NOS activity was decreased after DA ligation by 75% (P < 0.01). We conclude that chronic intrauterine pulmonary hypertension decreases eNOS in the fetal lung. We speculate that decreased NO production contributes to failure of postnatal adaptation in this experimental model of persistent pulmonary hypertension of the newborn.

Effects of inhaled nitric oxide on pulmonary edema and lung neutrophil accumulation in severe experimental hyaline membrane disease

To determine the effects of inhaled NO (iNO) on pulmonary edema and lung inflammation in experimental hyaline membrane disease (HMD), we measured the effects of iNO on pulmonary hemodynamics, gas exchange, pulmonary edema, and lung myeloperoxidase (MPO) activity in extremely premature lambs (115 d of gestation, 0.78 term). In protocol 1, we measured the effects of iNO (20 ppm) on lung vascular endothelial permeability to 125I-labeled albumin (indexed to blood volume using 57Cr-tagged red blood cells) during 1 h (n = 10) and 3 h (n = 14) of conventional mechanical ventilation with FiO2 = 1.00. In comparison with controls, iNO improved pulmonary hemodynamics and gas exchange, but did not alter lung weight-to-dry weight ratio or vascular permeability to albumin after 1 or 3 h of mechanical ventilation. To determine whether low dose iNO (5 ppm) would decrease lung neutrophil accumulation in severe HMD, we measured lung MPO activity after 4 h of mechanical ventilation with or without iNO (protocol 2). Low dose iNO improved gas exchange during 4 h of mechanical ventilation (PaO2 at 4 h: 119 +/- 35 mm Hg iNO versus 41 +/- 7 mm Hg control, p < 0.05), and reduced MPO activity by 79% (p < 0.05). We conclude that low dose iNO increases pulmonary blood flow, without worsening pulmonary edema, and decreases lung neutrophil accumulation in severe experimental HMD. We speculate that in addition to its hemodynamic effects, low dose iNO decreases early neutrophil recruitment and may attenuate lung injury in severe HMD.

Role of nitric oxide and cGMP system in regulation of ductus arteriosus tone in ovine fetus

Although endogenous nitric oxide (NO) modulates basal tone in the fetal pulmonary and systemic circulations, little is known about its role in regulating ductus arteriosus (DA) tone. Immunostaining of DA tissue from late-gestation fetal lambs demonstrated strong staining for endothelial NO synthase (eNOS) in DA endothelium. To study the physiological role of the NO and guanosine 3',5'-cyclic monophosphate (cGMP) system in the DA in vivo, we measured the hemodynamic effects of NG-nitro-L-arginine (L-NNA; 30 mg), a NOS inhibitor, methylene blue (40 mg), a guanylate cyclase inhibitor, and indomethacin (0.8 mg), a cyclooxygenase inhibitor, in 10 chronically prepared late-gestation fetal lambs. L-NNA increased main pulmonary artery (MPA) and aortic pressures (P < 0.05 vs. baseline) but did not change the pressure gradient between the MPA and the aorta. L-NNA caused a small decrease in DA flow and a slight rise in resistance across the DA. Methylene blue increased both MPA pressure and the pressure gradient between the MPA and the aorta from 0.3 +/- 0.2 (baseline) to 7.0 +/- 2.7 mmHg (P < 0.05). Indomethacin increased both MPA pressure and the pressure gradient between the MPA and the aorta from 1.1 +/- 0.4 (baseline) to 6.3 +/- 1.5 mmHg (P < 0.05) after 40 min. Indomethacin decreased DA flow and increased DA resistance. We conclude that eNOS is in fetal DA endothelial cells and that NOS inhibition causes constriction of the DA in vivo. DA constriction after NOS inhibition is minimal, especially in comparison with cyclooxygenase inhibition. Methylene blue also constricts the DA, suggesting that guanylate cyclase activity contributes to DA relaxation. We speculate that, although the NO and cGMP system modulates DA tone, prostaglandins may play a greater role.

Maturation-related changes in endothelial nitric oxide synthase immunolocalization in developing ovine lung

It is unknown whether high fetal pulmonary vascular tone is due in part to absent or decreased endothelial nitric oxide synthase (eNOS), the enzyme that produces nitric oxide in the vascular endothelium. To determine the timing of appearance and maturational changes of eNOS in the developing pulmonary circulation, we performed immunohistochemistry in lungs from fetal, neonatal, and adult sheep. Using a mouse monoclonal antibody against bovine aortic eNOS, we found immunoreactive eNOS selectively in the endothelium and it was present at all fetal ages. Immunoreactivity was seen as early as 29% gestation in the developing capillaries coursing through fetal mesenchyme. By 6 days after birth, immunoreactivity was decreased in most vessels and nearly absent in the distal pulmonary arteries of adult animals. We conclude that immunoreactive eNOS is present very early in fetal life and appears to decrease postnatally. We speculate that the early presence of eNOS in the fetal lung supports a possible role for endogenous nitric oxide activity in the regulation of vascular tone or angiogenesis in the developing pulmonary circulation.

Agarose infiltration improves morphology of cryostat sections of lung

BACKGROUND

Optimal morphology and immunohistochemistry of the lung requires the organ to remain fully distended. When the lung is prepared for frozen sections, especially during the stage of cryoprotection, liquid fixatives leak out and the lung tends to collapse. We sought to develop a new technique to improve the morphology of frozen sections of the lung while facilitating tissue handling and immunoreactivity.

EXPERIMENTAL DESIGN

Human, fetal sheep and adult rat lungs were distended with 1% low temperature melting agarose and vessels were perfused with a 1% paraformaldehyde solution.

RESULTS

The agarose infiltration permitted easy handling of the lung tissue, and maintained lung architecture during cryoprotection. Agarose infiltration and paraformaldehyde fixation provided excellent morphology, that was comparable to paraffin-embedded tissue. The structural preservation was especially noticeable with human lung that remained well distended with the agarose technique. Because of the mild fixation and good morphology, precise localization of antigenic sites was possible for the surfactant proteins SP-A, SP-C and SP-D, cytokeratin, and alveolar macrophage markers.

CONCLUSIONS

This procedure can improve special fixation and embedding protocols for lung immunocytochemistry and immunofluorescence.